func getHostsSlice(records []dns.SrvRecord) []string {
	hosts := make([]string, len(records))
	for i, r := range records {
		hosts[i] = net.JoinHostPort(r.Host, string(r.Port))
	}
	return hosts
}

// returns an online host (and corresponding port) from a slice of DNS records
func getHostFromSrv(records []dns.SrvRecord) (host string) {
	hosts := getHostsSlice(records)

	if isMaxObjectSize(length) {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrEntityTooLarge), r.URL)
		return
	}

	if isRemoteCopyRequired(ctx, srcBucket, dstBucket, objectAPI) {
		var dstRecords []dns.SrvRecord
		dstRecords, err = globalDNSConfig.Get(dstBucket)
		if err != nil {
			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
			return
		}